Online learning using information fusion for equipment predictive maintenance in railway operations

ABSTRACT

An aspect of an online learning system includes collecting data, via a computer processing device, from a plurality of data sources including multiple disparate detectors, the data including at least one of historical alarm data, failures, maintenance records, and environment observations. The data is stored in tables each corresponding to a subject of measurement. The online learning system also includes identifying common fields shared across the tables, merging at least a portion of the data across the tables having the common fields, and creating an integrated data model based on results of the merging.

CROSS-REFERENCE TO RELATED APPLICATION

The present application is a Continuation application of U.S. patentapplication Ser. No. 13/873,851, filed on Apr. 30, 2013, which claimsthe benefit of U.S. Patent Application Ser. No. 61/751,704 filed on Jan.11, 2013, which are hereby incorporated by reference herein in theirentirety.

BACKGROUND

The present invention relates to data processing and, more specifically,to online learning using information fusion for equipment predictivemaintenance in railway operations.

The ability to make sense of large amounts of data, or “big data” as itis often referred to, is a challenging task. With the ever-increasingnumbers of available data sources and rapid, ongoing enhancements madein the computing power of data generation devices, as well as the widevariety of types of data (e.g., both structured and unstructured) thatcan be collected today, managing big data can require advancedtechniques and technologies. Clearly, the ability to analyze andinterpret these large amounts of complex and variable data has thepotential to be of great value to an entity or entities responsible foror having an interest in the data. For example, in many industries thatmonitor the health of equipment or other assets, accurate analyses ofthis data can be used to predict and, thus, take measures to preventequipment or asset failures.

SUMMARY

According to one embodiment of the present invention, a method isprovided. The method includes collecting data, via a computer processingdevice, from a plurality of data sources including multiple disparatedetectors, the data including at least one of historical alarm data,failures, maintenance records, and environmental observations. The datais stored in tables each corresponding to a subject of measurement. Themethod also includes identifying common fields shared across the tables,merging at least a portion of the data across the tables having thecommon fields, and creating an integrated data model based on results ofthe merging.

According to another embodiment of the present invention, a system isprovided. The system includes a computer processing systemcommunicatively coupled to data sources, and logic executable by thecomputer processing system. The logic is configured to implement amethod. The method includes collecting data from a plurality of datasources including multiple disparate detectors, the data including atleast one of historical alarm data, failures, maintenance records, andenvironmental observations. The data is stored in tables eachcorresponding to a subject of measurement. The method also includesidentifying common fields shared across the tables, merging at least aportion of the data across the tables having the common fields, andcreating an integrated data model based on results of the merging.

According to a further embodiment of the present invention, a computerprogram product is provided. The computer program product includes astorage medium embodied with machine-readable program instructions,which when executed by a computer causes the computer to implement amethod. The method includes collecting data from a plurality of datasources including multiple disparate detectors, the data including atleast one of historical alarm data, failures, maintenance records, andenvironmental observations. The data is stored in tables eachcorresponding to a subject of measurement. The method also includesidentifying common fields shared across the tables, merging at least aportion of the data across the tables having the common fields, andcreating an integrated data model based on results of the merging.

Additional features and advantages are realized through the techniquesof the present invention. Other embodiments and aspects of the inventionare described in detail herein and are considered a part of the claimedinvention. For a better understanding of the invention with theadvantages and the features, refer to the description and to thedrawings.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

The subject matter which is regarded as the invention is particularlypointed out and distinctly claimed in the claims at the conclusion ofthe specification. The forgoing and other features, and advantages ofthe invention are apparent from the following detailed description takenin conjunction with the accompanying drawings in which:

FIG. 1 depicts a block diagram of a system upon which predictivemodeling for asset management may be implemented according to anembodiment of the present invention;

FIG. 2 depicts a flow diagram describing a process for implementingpredictive modeling for asset management according to an embodiment ofthe present invention;

FIG. 3 depicts a failure rate control chart with sample data foridentifying changes in failure rate of an asset according to anembodiment of the present invention;

FIG. 4 depicts components and functions for online learning andinformation fusion according to an embodiment of the present invention;

FIG. 5 depicts records of data that may be merged by information fusiontechniques according to an embodiment of the present invention;

FIG. 6 depicts a flow diagram of a process for implementing alarmprediction processes according to an embodiment of the presentinvention; and

FIGS. 7A and 7B each depicts a two-dimensional chart of sampled dataaccording to an embodiment of the present invention.

DETAILED DESCRIPTION

Exemplary embodiments provide predictive modeling using severalanalytical approaches including, e.g., correlation analysis, causalanalysis, time series analysis, survival modeling, and machine learningtechniques to automatically learn rules and build failure predictionmodels based on exploration of historical multi-detector measurements,equipment failure records, maintenance records, environmentalconditions, etc. Additionally, the analytics and models can also be usedfor detecting root-causes of several failure modes of components, whichcan be proactively used by a maintenance organization to optimizetrade-offs related to maintenance schedules, costs, and shop capacity.

According to an exemplary embodiment, predictive modeling for assetmanagement (also referred to herein as “predictive modeling”) isprovided. The predictive modeling provides the ability to analyze andinterpret large amounts of complex and variable data concerning an assetor group of assets, as well as conditions surrounding the assets. Inparticular, the predictive modeling provides the ability to performlarge-scale, multi-detector predictive modeling and related tasks topredict when one or more of the assets might fail. Further, thepredictive modeling incorporates statistical learning to predict assetfailures based on large-scale, multi-dimensional sparse time seriesdata.

Effective utilization of data provides valuable tools for operationalsustainability. The predictive modeling develops the concept ofcomposite detectors and integrates large-scale information collectedfrom multiple detectors to predict undesired conditions of equipment andunexpected events, such as alarms that cause service interruptions.

The exemplary predictive modeling techniques described herein may beimplemented for any industry that collects and processes large amountsof data from detectors in order to determine and maintain the health ofone or more assets. For example, the predictive modeling processes maybe implemented by the railroad industry, airline industry, or othertransportation industry. The exemplary predictive modeling processesalso have applications in the area of manufacturing.

Turning now to FIG. 1, a system 100 upon which the predictive modelingprocesses may be implemented will now be described in an exemplaryembodiment. The system 100 of FIG. 1 includes a host system 102 incommunication with data sources 104A-104 n (referred to collectively asdata sources 104) over one or more networks 110.

The host system 102 may be implemented as a high-speed computerprocessing device (e.g., a mainframe computer) that is capable ofhandling a large volume of data received from the data sources 104. Thehost system 102 may be implemented by any entity that collects andprocesses a large amount of data from a multitude of data sources 104 tomanage, or may be offered as a service to such entity by, e.g., anapplication service provider (ASP).

The data sources 104 may include devices configured to capture raw datafrom aspects of the asset, as well as any conditions surrounding theasset. In the railroad industry, for example, assets may be railroadtracks, as well as cars that travel along the tracks (and theirconstituent parts). In the airline industry, the assets may includeairplanes and corresponding parts that are inspected, as well as runwayconditions. The data sources 104 may include detectors, such as probes,sensors, and other instrumentation that are configured to measurequalitative aspects of the assets or surrounding conditions, such astemperature, weight or load, strain, dimensions (e.g., indications ofwear), sound, and images, to name a few. In the railroad industry, themeasurements may be taken with regard to railroad track components andvehicle wheels. In this embodiment, detectors that may be used assources of data include machine vision detectors (MVDs), wheel impactload detectors (WILDs), optical geometry detectors (OCDs), truckperformance detectors (TPDs), acoustic bay detectors (ABDs), hot boxdetectors, warm bearing detectors, and hot wheel/cold wheel detectors.In addition to the qualitative aspects, the data sources 104 may capturetime, physical location, object location, and other informationregarding the subject of measurement, as will be described herein. Inthis regard, the data sources 104 reflect multi-dimensional detectiondevices, as they are configured to collect a wide variety of differenttypes of information.

The data sources 104A-104 n may include (or may be coupled to)corresponding communication components 116A-116 n (referred tocollectively as communication components 116) for transmitting captureddata over one or more networks. In an embodiment, the communicationcomponents 116 may include, e.g., transceivers, antennae, and/or networkcards for receiving and conveying data using wireless and/or wirelinetransmission technologies including radio frequency (RF), WiFi,Bluetooth, cellular, satellite, copper wiring, co-axial cabling, etc.For example, a probe on one of the data sources 104 collects data from alocation (e.g., a location on a railroad track) and transfers the datato the corresponding communication component 116 for transmission overnetworks 110 to the host system 102. In an embodiment, as shown in FIG.1, the networks 110 may include one or more reader devices 108 forreceiving the data from the data sources 104. In the railroad industry,e.g., the reader devices 108 may be RF readers positioned at definedlocations (e.g., at fixed-length intervals) along the railroad track.The RF readers 108 read data from corresponding data sources 104 (viathe communication components 116, which may be RF antennae) as the datasources 104 (embedded in the vehicles) pass within communicative rangeof the reader devices 108.

In an embodiment, the data captured by the data sources 104 may betransmitted as raw data to the host system 102 or may be processed priorto transmission. The data sources 104A-104 n may also includecorresponding computer processors 118A-118 n (collectively referred toas computer processors 118) for processing the raw data and/orformatting the data for transmission over the networks 110.Alternatively, if the data sources 104 do not include a computerprocessor, the captured data may be transmitted via the communicationcomponents 116 to a computer processor configured for receiving thedata.

In another embodiment, some of the data sources 104 may alternativelyinclude other information sources, such as cameras or portablecommunication devices (e.g., cellular telephones, smart phones, or otherportable devices) operated by users who are in direct observation of theasset or surrounding conditions who have observed an event that may havean impact on safety. The data collected by the host system 102 fromthese portable devices may include texts, images, messages, or otherinformation provided by a user of a communication device. For example,an observer near a railroad track may witness a previously unreporteddefect or anomaly, record an image of the defect, and transmit the imagewith date/time information, and alternatively a text description, to thehost system 102 or another entity which forwards the information to thehost system 102.

The networks 110 may include any type of networks, such as local areanetworks, wide area networks, virtual private networks, and theInternet. In addition, the networks 110 may be configured to supportwireless communications, e.g., via radio frequency (RF) communications,cellular networks, satellite networks, and global positioning (GPS)systems.

The host system 102 executes logic 112 for implementing the exemplarypredictive modeling, as well as other processes, as described herein.The logic 112 includes a user interface component for enablingauthorized users to set preferences used in configuring data sources 104employed in the processes described herein, as well as generating andexecuting predictive models, performing analysis on the histories ofpreviously implemented models, and facilitating the generation of newmodels, or evolvement of existing models, to increase the ability forthe managing entity to ensure reliable operation. The preferences mayinclude designating a frequency of data collection by the data sources104. The logic 112 may also be configured to utilize the informationacquired from execution of the models to analyze and adopt maintenanceand repair plans for components of the asset. These, and other featuresof the predictive modeling, will be described further herein.

The host system 102 is communicatively coupled to a storage device 114that stores various data used in implementing the predictive modeling.For example, the storage device 114 may store models, performancehistories (e.g., alarm histories, repair histories, etc.), and otherinformation desired. The storage device 114 may be directly incommunication with the host system 102 (e.g., via cabling) or may belogically addressable by the host system 102, e.g., as a consolidateddata source over one or more networks 110.

Predictive models are generated from history data collected from thedata sources 104. Patterns of data from the measurements and resultingrepair work or maintenance schedules can be used in a predictive mannerfor estimating when maintenance should be performed. In addition, as newdata is received, the predictive models can be updated to reflect anychanges discovered. A user interface of the logic 112 may be used topresent organized history data, as well as alert information. Thecreated model may be stored as one of several stored models, e.g., inthe storage device 114 of FIG. 1. As new data is received from the datasources 104, it can be applied to the predictive models and may be usedto update the models in order to ascertain future maintenance needs orcritical issues that require immediate attention.

Turning now to FIG. 2, a flow diagram describing a process forimplementing the predictive modeling will now be described in anexemplary embodiment. In one embodiment, the services may provide aweb-based user interface for receiving information from a user increating and implementing a model. Once accessed, the user interface,via the logic 112, prompts a user through the process. The processassumes that history data has been collected over a period of time. Thehistory data may include detector data, alarm information, andmaintenance data. It will be understood that the data collected may besparse time series data. For example, in the railroad industry, thedetectors may not be evenly distributed across the network, thus thenumber of readings may vary dramatically across different locations inthe railroad system. Also, for some types of detectors, the time seriesof readings may be sparse due to, e.g., infrequent use of the asset inwhich the detector readings are taken, as compared to other assets. Thepredictive modeling is configured to handle the sparsity in the detectordata.

At step 202, the logic 112 generates a factor matrix for each univariatetime series data in a set of sparse time series data collected from agroup of detectors over time. In an embodiment, this may be implementedusing supervised matrix factorization (SMF) techniques. In this example,let X denote the multi-dimensional time series from different types ofdetectors. These detectors generate p univariate time series (e.g., pinfluential factors) denoted as X=(X₁, X₂, . . . , X_(p)). Some timeseries could be sparse (e.g., they may be sparse as a result of beingsparsely sampled over time, or they may represent incomplete or noisydata). Let Y be the label vector for the asset failures (e.g., 1indicates a failure, and 0 indicates good condition). The SMF for theith, i=1, 2, . . . p, univariate time series may be represented as:

  X_(i) ≈ H_(i)V_(i)^(T)   Y ≈ logit(H_(i)W_(i)^(T))$\left( {H_{i}^{*},V_{i}^{*},W_{i}^{*}} \right) = {{\underset{H_{i},V_{i},W_{i}}{{\arg \; \min}\;}\mu \; {L_{R}\left( {X_{i},{H_{i}V_{i}^{T}}} \right)}} + {\left( {1 - \mu} \right){L_{CA}\left( {Y,{{logit}\left( {H_{i\;}W_{i}^{T}} \right)}} \right)}} + {{Reg}\left( {H_{i},V_{i},W_{i}} \right)}}$

H_(i) is the latent representation of time series, where each rowdefines the latent features of the original time series in X_(i).Similarly, V_(i) is the latent representation of time points. SMF isused to find optimal latent representation matrices in order to bestapproximate the matrices X and Y via a loss function optimizationtechnique. The latent representation matrix H is a good estimate ofobserved time series, and useful features may be extracted from H, suchas trend and diversification.

-   -   ‘T’ is the transpose of a matrix;    -   W is a set of linear logistic regression weights;    -   logit is the cell-wise logistic function;    -   L_(R) is the reconstruction loss, which makes sure that the        latent feature matrices H and V could reconstruct X;    -   L_(CA) is the supervised classification accuracy loss term,        which enforces the latent time series representation H to be        corrected such that a set of all-versus-one logistic regression        weights W can maximize the classification accuracy on the data        set;    -   Reg is the regularization term, which ensures that the latent        matrices do not overfit; and    -   μ is the weight of L_(R) and με(0,1).

At step 204, a subset of the time series data is identified as a featureselection, which is determined based on a loss function. For eachpredictor X (where X_(i) is the ith predictor), calculate the minimumloss, then rank the predictors in the order of the optimized loss. Thepredictor importance indicates the relative importance of each predictorin predicting the bad trucks (i.e., the best predictors to approximatethe label vector Y in terms of the loss).

At step 206, the logic 112 generates a predictive model from the subsetof time series data. The predictive model is configured to predict afailure using, e.g., data mining, machine learning, and/or statisticalmodeling. Different predictive models may be generated for assetfailures. For example, in the railroad industry, data from multipledetectors (e.g., WILD, MV, and OGD) may be used in the analysis. Supposea decision tree method is used to predict the occurrence of truckfailures in three months with sparse time series data, and theprediction accuracy of the model is high for both training and testingdata. The model may ben correctly classify most bad truck records asfailed in both the training and test datasets. Other predictive methodscan be used as well, such as neural network, Support Vector Machine(SVM), and statistical models (e.g., Cox Proportional Hazards model orAndersen-Gill model). The predictive model may then be used to renderdecisions regarding inspection and repair of the asset.

At step 208, the logic 112 receives new data from the detectors andcompares the model predictions to actual data that is newly received.The new data may be real-time or near real-time data streamed from oneor more of the data sources 104 to the host system 102 over the networks110. As shown, for example, in FIG. 3, a failure rate chart 300 for anasset is generated based on the one-sample weighted rank test.

A non-parametric one-sample weighted rank test may be represented as:

H₀:h₀(t) = h(t), for  t ≤ τ H₁:h₀(t) < h(t), for  t ≤ τ${Z(\tau)} = \frac{{\sum\limits_{i - 1}^{D_{I}}{{W\left( t_{i} \right)}\begin{matrix}d_{i} \\{Y\left( t_{i} \right)}\end{matrix}}} - {\int_{0}^{\tau}{{W(s)}\ {h_{0}(s)}{s}}}}{\sqrt{\int_{0}^{\tau}{{W^{2}(s)}\frac{h_{0}(s)}{Y(s)}\ {s}}}}$

An operational characteristics function is expressed as:

$n = {\left( {Z_{\alpha} + Z_{\beta}} \right)^{2} \cdot \frac{\int_{0}^{\tau}{{w^{2}(s)}\ {{h_{0}(s)}/{y(s)}}{s}}}{\left\{ {\int_{0}^{\tau}{{{w(s)}\left\lbrack {{h(s)} - {h_{0}(s)}} \right\rbrack}\ {s}}} \right\}^{2}}}$

The statistic follows the standard normal distribution for large samplesunder H₀. τ is selected as the largest failure time in the monitoringsubgroup.

At step 210, the logic 112 determines a change in a failure rate basedon a one-sample weighted rank test. At step 212, it is determined if thechange exceeds a threshold value (referred to herein as ‘upper controllimit’). The threshold value may be defined by an authorized user of thelogic 112. If the change does not exceed the threshold value, theprocess returns to step 208.

If, however, the change exceeds the threshold value, the logic 112updates the predictive model to reflect the change at step 214. As shownin FIG. 3, the failure rate of the asset became worse over time sincethe Z value is gradually increasing, and at the subgroup 63, it exceedsthe upper control limit (UCL=2.326) for the first time. Subgroup refersto a term used in control charts for Statistical Process Control (SPC).The subgroup is a sample with a fixed sample size (i.e., the number ofobservations is fixed). In this embodiment, the subgroup represents asample containing a fixed number of failures.

The model can be updated by using, e.g., the Bayesian inference methodas shown below (where Φ denotes the predictive model parameters whichneed to be updated):

p(Φ|D,M)∝p(D|M,Φ)p(Φ|M)

D represents the data, and M represents the model.

p(Φ|D,M) represents the updated joint probability density function.

In addition, p(D|M,Φ) represents the data likelihood function based onthe performance model, and the function p(Φ|M) represents the priorprobability density function selected for the model.

As indicated above, the predictive modeling process of FIG. 2 assumesthat history data has been collected over a period of time and mayinclude, e.g., detector data, alarm information, and maintenance data.In addition, the data collected may be sparse time series data. Anonline learning system may be employed using information fusiontechniques to integrate the history data that is received from multipletypes of disparate detection devices. The online learning system andprocess is configured to integrate information collected from spatially-and temporally-incompatible detection devices to enable predictivemaintenance for asset management. The online learning system and processutilizes historical detector data along with failure data to determinepatterns of detector readings that may be subcritical, thereby leadingto failures across multiple detectors with sparse sampling. The fusiontechniques provide the ability to study assets that move across thedetector network and enable information from these assets to beintegrated across time and space. By fusing this information collectedfrom multiple detectors, an integrated insight into equipment conditionscan be gleaned. In addition, the on line learning system and processcombines offline and online learning engines to generate failure alertsfor equipment predictive maintenance.

The online learning system and process is described herein with respectto the railroad industry. However, it will be understood that the onlinelearning system may be adapted for other industries as well. Thus, theembodiments described herein are for illustrative purposes and are notintended to limit the scope of thereof.

Turning now to FIG. 4, a system 400, and functional components thereof,through which the online learning and fusion processes may beimplemented will now be described in an embodiment.

The system 400 includes an integrated data model 402 that is generatedfrom a variety of data 404 collected offline. As shown in FIG. 4, thedata 404 includes wayside detector data 404 a, traffic and network data404 b, track inspection data 404 c, weather data 404 d, set-out andfailure data 404 e, and tear down/repair data 404 f. It will beunderstood that additional (or fewer) data elements may be employed torealize the advantages of the embodiments described herein. The data 404may be collected by the data sources 104 of FIG. 1 and transmitted tothe host system 102 for processing by the logic 112. The logic 112generates the integrated data model 402 as described herein.

The integrated data model 402 is generated in part by merging disparatedata from multi-dimensional detection devices (e.g., data sources 104 ofFIG. 1). The data sources 104 collect information, which data is storedas history data in one or more storage locations (e.g., storage device114). The data may be stored in various tables. FIG. 5 illustratestables of sample data to be merged in a railroad industry environment. Afirst table 502 provides data regarding a vehicle wheel (HOT_WHEEL)collected from January 1^(st) through December 31^(st) of a given year.The detector used in the collection may be a hot wheel detector (HWD)that is attached to a railroad track at a specified, fixed location, andincludes a temperature sensor to measure temperature of the wheel as itpasses the location on the track. The information stored in the table502 may include message identification information, equipmentidentification information, and temperature measured, to name a few.

A second table 504 provides data regarding a vehicle axle (HBD_AXLE)collected from January 15^(th) through October 30^(th) of the same givenyear. The detector used in the collection may be a hot box detector(HBD) for an axle that is attached to a railroad track at a specified,fixed location, and includes a temperature sensor to measure temperatureof the axle as it passes the location on the track.

A third table 506 provides data regarding impact load for a wheel(WILD_WHL) collected from January 1^(st) through December 31^(st) of twoyears covering the same given year. The detector used in the collectionmay be a wheel impact load detector (WILD) that is attached to arailroad track at a specified, fixed location, and includes a sensorthat determines an amount of load or force on the track (e.g., measuredin KIPS).

A fourth table 507 provides data regarding equipment or railcar that wascollected from the same two years as the table above. The detector usedin the collection may be a wheel impact load detector (WILD) that isattached to a railroad track at a specified, fixed location, andincludes a sensor that determines the measurements at equipment level,such as equipment speed.

A fifth table 510 provides data regarding a noise signature emitted bybearings collected from the same two years. The detector used in thecollection may be an acoustic bearing detector (ABD) that is attached toa railroad track at a specified, fixed location, and includes a sensorthat captures any anomalies in the noise signature emitted by bearing inmotion and the detector processes this information internally and issuesalarms when an anomalous acoustic signature is detected.

As indicated above, the detectors associated with these tables acquirevery different information (e.g., temperature readings and load bearinginformation). The logic 112 is configured to merge the data in thesetables where shared fields are known. For example, the data in table 502can be merged with data in table 504 through common fields HBD_MSG_ID,EQP_INIT, EQP_NBR, EQP_ACLE_NBR, and AXLE_SIDE, which occur in bothtables. Likewise, tables 502 and 504 may be merged with table 506through common fields EQP_AXLE_NBR and AXLE_SIDE. In addition, table 506can be merged with table 507 through common fields EDR_MSG_ID andEQP_SEQ_NBR, as well as with table 510 through common fields EDR_MSG_ID,EQP_AXLE_NBR, and AXLE_SIDE. By way of example, using the vehicleidentifier, monthly data regarding each vehicle can be aggregated foreach detector.

The logic 112 utilizes the integrated data model 402 to perform failurepattern analysis 406 and failure causal analysis 410. Insights from theperspectives of preventative maintenance, procurement decision, andrailway operations can be obtained by discovering correlations in thehistorical data that associates failures with equipment physicalparameters (e.g., weight, flange thickness, flange height, rimthickness, etc.), equipment operation parameters (e.g., speed, dynamicload, bearing temperature, etc.), and external parameters (e.g.,weather, usage history). Traffic & network data 404 b includes data thatmeasures the traffic volumes or number of railcars passing through therail segments. Track inspection data 404 c provides inspection recordswhich may indicate the condition of the tracks. Weather data 404 dincludes any weather-related information that may have an impact onrailway operating conditions (e.g., those that might result inderailment). The set-out & failure data 404 e and the tear down/repairdata 404 f provide maintenance records including equipment failures andrepair information.

Failure pattern analysis 406, subject matter expert (SME)-rendereddecisions 408, failure causal analyses 410, learning failure predictionmodels 412, and failure causal map 414 are associated with an offlinelearning engine based on the large volume of data collected for theseelements. The failure pattern analysis component 406 of the offlinelearning engine is an analytics engine configured to discover failurepatterns such as seasonality patterns of failures. The failure causalanalyses component 410 of the offline learning engine identifies thefactors that drive the patterns while leveraging SME knowledge in 408.The failure causal map 414 provides a tool to visualize the causalfactors and failure patterns. The learning failure prediction models 412develop the failure prediction engine based on the failure patterns andcausal factors. Once the offline learning engine is developed, it isused in an online fashion with real-time data (e.g., live sensor data418). When the detector data 418 is received, it is fed to theanalytical models 420. Prediction outputs and decision recommendationsresulting from the models 420 is displayed in a predictedfailure/optimized preventative maintenance program 416.

In order to reduce immediate service interruptions and to provide betterprediction of asset failures, one goal is to maximize the occurrences ofcrew set-outs and reduce the inspection and maintenance costs. Withreference to the railroad industry, e.g., components of analyticsinvolved in this goal relate to alarm prediction, bad truck prediction,and bad wheel prediction (as described above with respect to FIGS. 1-3).In alarm prediction, multiple detectors (HBD, ABD, and WILD) can aid inpredicting the most severe alarm related to hot bearings within ameaningful advanced amount of time (e.g., 7 days in advance of actualalarm/incident occurrence to reduce the immediate train stops). In badtruck prediction analysis, wheels and trucks are replaced when theycreate high impact or wear out. To identify patterns in wheel movementerror, wheel dimension and wheel impact load data may be used to detecttruck performance issues earlier using multiple detectors, such as MV,OGD, TPD, and WILD. To identify patterns in wheel dimensions, movementerrors and wheel impact load that predict the wheel defects earlier maybe determined from data received from multiple detectors, such as MV,OGD, and WILD.

Railroads issue Level 1 (L1) alarms when the detector readings reach themost severe category and thus immediate train stoppage is generallyrequired. Predicting an L1 alarm in advance is desirable so thatoperators have sufficient time to respond. One goal in developing analarm prediction model is to keep false alarm rates low due toconstraints in corresponding resources. Another goal is to provide humaninterpretable rules to facilitate decision processes by operators.

In an embodiment, alarm prediction processes are provided. The alarmprediction processes are configured to accomplish the above-referencedgoals. Alarm prediction may be summarized as a classification problemwhere one class relates to detector readings history with alarms, andthe other class relates to detector readings history without alarms. Theexemplary alarm prediction processes utilize Support Vector Machine(SVM) techniques. In the alarm prediction, two sets of parameters areprovided and may be customized. One set is the prediction time window(i.e., how many days in advance the alarm prediction is generated).Based on the trade-offs between operational constraints versus accuracyof prediction, the process offers predictions for 3 or 7 days inadvance, which in turn may provide enough buffering time to prepare forinspections based on operation conditions. The second set of parametersis the historical detector reading time window that indicates how manydays of past detector readings may be used to provide a forecast. Basedon the trade-offs between availability of historic data in detector datastorage systems versus the accuracy of prediction, the process mayinclude two options. For purposes of illustration the options are 7 daysand 14 days. By combining the two sets of parameters, there are now foursettings, i.e., 7-7, 7-3, 14-7, and 14-3. The first number of eachsetting indicates the reading time window, and the second number in eachsetting reflects the prediction time window. For example, 7-3 meansusing the past 7 days of readings, an alarm prediction of 3 days in thefuture can be provided.

Turning now to FIG. 6, the alarm prediction processes will now bedescribed in an embodiment. At step 602, data is aggregated fromdetectors (e.g., the data sources 104 of FIG. 1 including the dataelements 404 in FIG. 4), and features are extracted (e.g., usingquantiles) for each numeric value variable. The features may each be avector of equal length. In the feature extraction, historicalmulti-detector readings, e.g., ABD, HBD, and WILD, as well as extractfeatures are combined and aggregated using quantiles for each numericvalue variable. At step 604, sample features are linearly projected to alower dimensional space (e.g., a learned non-linear decision boundary)while maintaining a comparable learning performance, which in turn mayreduce both the time and memory complexities required by the learningmodel.

At step 606, a prediction is generated based on its location in thefeature space to the support vectors (e.g., the key samples that lie inthe border area between positives and negatives). In step 608, adecision boundary is logicalized. Human interpretable rules areextracted given the complex SVM classification results. As shown in FIG.7A for example, a grid 700A illustrates feature space in which allblocks constitute the feasible feature space, and each block is asample. Based on learning decisions, positive samples are darkened (704a). A curve 706 a represents a separating or decision boundary. Thefeature space of the grid 700A illustrates a coarse logical rule search.Using the same two-dimensional learning problem, a grid 700B in FIG. 7Billustrates a feature space comprising smaller (finer grid search)blocks 702 b. In comparison to the grid 700A, the decision boundary 706b is more precise. The rule logicalization is, thus, scalable to adesired granular level.

From execution of the rules, the logic 112 may calculate the probabilityor risk. For example, the logic 112 may predict whether a bearing willissue a L1 alarm within a defined future time period based on itslocation (in feature space) to the support vectors (i.e., the keysamples that lie in the border area between positives and negatives). Inaddition to predicting whether an alarm will be issued or not, thecorresponding confidence is estimated based on the relative position tothe support vectors at step 610.

As will be appreciated by one skilled in the art, aspects of the presentinvention may be embodied as a system, method or computer programproduct. Accordingly, aspects of the present invention may take the formof an entirely hardware embodiment, an entirely software embodiment(including firmware, resident software, micro-code, etc.) or anembodiment combining software and hardware aspects that may allgenerally be referred to herein as a “circuit,” “module” or “system.”Furthermore, aspects of the present invention may take the form of acomputer program product embodied in one or more computer readablemedium(s) having computer readable program code embodied thereon.

Any combination of one or more computer readable medium(s) may beutilized. The computer readable medium may be a computer readable signalmedium or a computer readable storage medium. A computer readablestorage medium may be, for example, but not limited to, an electronic,magnetic, optical, electromagnetic, infrared, or semiconductor system,apparatus, or device, or any suitable combination of the foregoing. Morespecific examples (a non-exhaustive list) of the computer readablestorage medium would include the following: an electrical connectionhaving one or more wires, a portable computer diskette, a hard disk, arandom access memory (RAM), a read-only memory (ROM), an erasableprogrammable read-only memory (EPROM or Flash memory), an optical fiber,a portable compact disc read-only memory (CD-ROM), an optical storagedevice, a magnetic storage device, or any suitable combination of theforegoing. In the context of this document, a computer readable storagemedium may be any tangible medium that can contain, or store a programfor use by or in connection with an instruction execution system,apparatus, or device.

A computer readable signal medium may include a propagated data signalwith computer readable program code embodied therein, for example, inbaseband or as part of a carrier wave. Such a propagated signal may takeany of a variety of forms, including, but not limited to,electro-magnetic, optical, or any suitable combination thereof. Acomputer readable signal medium may be any computer readable medium thatis not a computer readable storage medium and that can communicate,propagate, or transport a program for use by or in connection with aninstruction execution system, apparatus, or device.

Program code embodied on a computer readable medium may be transmittedusing any appropriate medium, including but not limited to wireless,wireline, optical fiber cable, RF, etc., or any suitable combination ofthe foregoing.

Computer program code for carrying out operations for aspects of thepresent invention may be written in any combination of one or moreprogramming languages, including an object oriented programming languagesuch as Java, Smalltalk, C++ or the like and conventional proceduralprogramming languages, such as the “C” programming language or similarprogramming languages. The program code may execute entirely on theuser's computer, partly on the user's computer, as a stand-alonesoftware package, partly on the user's computer and partly on a remotecomputer or entirely on the remote computer or server. In the latterscenario, the remote computer may be connected to the user's computerthrough any type of network, including a local area network (LAN) or awide area network (WAN), or the connection may be made to an externalcomputer (for example, through the Internet using an Internet ServiceProvider).

Aspects of the present invention are described below with reference toflowchart illustrations and/or block diagrams of methods, apparatus(systems) and computer program products according to embodiments of theinvention. It will be understood that each block of the flowchartillustrations and/or block diagrams, and combinations of blocks in theflowchart illustrations and/or block diagrams, can be implemented bycomputer program instructions. These computer program instructions maybe provided to a processor of a general purpose computer, specialpurpose computer, or other programmable data processing apparatus toproduce a machine, such that the instructions, which execute via theprocessor of the computer or other programmable data processingapparatus, create means for implementing the functions/acts specified inthe flowchart and/or block diagram block or blocks.

These computer program instructions may also be stored in a computerreadable medium that can direct a computer, other programmable dataprocessing apparatus, or other devices to function in a particularmanner, such that the instructions stored in the computer readablemedium produce an article of manufacture including instructions whichimplement the function/act specified in the flowchart and/or blockdiagram block or blocks.

The computer program instructions may also be loaded onto a computer,other programmable data processing apparatus, or other devices to causea series of operational steps to be performed on the computer, otherprogrammable apparatus or other devices to produce a computerimplemented process such that the instructions which execute on thecomputer or other programmable apparatus provide processes forimplementing the functions/acts specified in the flowchart and/or blockdiagram block or blocks.

The flowchart and block diagrams in the Figures illustrate thearchitecture, functionality, and operation of possible implementationsof systems, methods and computer program products according to variousembodiments of the present invention. In this regard, each block in theflowchart or block diagrams may represent a module, segment, or portionof code, which comprises one or more executable instructions forimplementing the specified logical function(s). It should also be notedthat, in some alternative implementations, the functions noted in theblock may occur out of the order noted in the figures. For example, twoblocks shown in succession may, in fact, be executed substantiallyconcurrently, or the blocks may sometimes be executed in the reverseorder, depending upon the functionality involved. It will also be notedthat each block of the block diagrams and/or flowchart illustration, andcombinations of blocks in the block diagrams and/or flowchartillustration, can be implemented by special purpose hardware-basedsystems that perform the specified functions or acts, or combinations ofspecial purpose hardware and computer instructions.

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting of the invention. Asused herein, the singular forms “a”, “an” and “the” are intended toinclude the plural forms as well, unless the context clearly indicatesotherwise. It will be further understood that the terms “comprises”and/or “comprising,” when used in this specification, specify thepresence of stated features, integers, steps, operations, elements,and/or components, but do not preclude the presence or addition of onemore other features, integers, steps, operations, element components,and/or groups thereof.

The corresponding structures, materials, acts, and equivalents of allmeans or step plus function elements in the claims below are intended toinclude any structure, material, or act for performing the function incombination with other claimed elements as specifically claimed. Thedescription of the present invention has been presented for purposes ofillustration and description, but is not intended to be exhaustive orlimited to the invention in the form disclosed. Many modifications andvariations will be apparent to those of ordinary skill in the artwithout departing from the scope and spirit of the invention. Theembodiment was chosen and described in order to best explain theprinciples of the invention and the practical application, and to enableothers of ordinary skill in the art to understand the invention forvarious embodiments with various modifications as are suited to theparticular use contemplated

The flow diagrams depicted herein are just one example. There may bemany variations to this diagram or the steps (or operations) describedtherein without departing from the spirit of the invention. Forinstance, the steps may be performed in a differing order or steps maybe added, deleted or modified. All of these variations are considered apart of the claimed invention.

While the preferred embodiment to the invention had been described, itwill be understood that those skilled in the art, both now and in thefuture, may make various improvements and enhancements which fall withinthe scope of the claims which follow. These claims should be construedto maintain the proper protection for the invention first described.

What is claimed is:
 1. A method, comprising: collecting data, via acomputer processing device, from a plurality of data sources includingmultiple disparate detectors, the data including at least one ofhistorical alarm data, failures, maintenance records, and environmentalobservations, the data stored in tables each corresponding to a subjectof measurement; identifying common fields shared across the tables;merging at least a portion of the data across the tables having thecommon fields; and creating an integrated data model based on results ofthe merging.
 2. The method of claim 1, wherein the tables include afirst table and a second table, the first table storing informationabout a first subject of measurement, the information collected over afirst period of time, and the second table storing information about asecond subject of measurement that is different than the first subjectof measurement, the information about the second subject of measurementcollected over a second period of time that partially overlaps with thefirst period of time; wherein the merging includes merging data sharingan overlapping period of time between the first period of time and thesecond period of time.
 3. The method of claim 1, wherein the tablesinclude a first table and a second table, the first table storinginformation about a first subject of measurement, the informationcollected by a first detection device, and the second table storinginformation about a second subject of measurement that is different thanthe first subject of measurement, the information about the secondsubject of measurement including a measurement of a physical parameterthat is common to the first subject of measurement and the secondsubject of measurement; wherein the merging includes merging data thatshares the physical parameter that is common to the first subject ofmeasurement and the second subject of measurement.
 4. The method ofclaim 1, further comprising applying the model to new data received fromthe data sources and performing failure pattern analysis and failurecausal analysis on the new data.
 5. The method of claim 1, wherein thedata sources reside in a railroad environment and physical parametersassociated with train wheels and tracks as the subject of measurementinclude at least one of: weight; flange thickness; flange height; andrim thickness.
 6. The method of claim 1, wherein the data sources residein a railroad environment and operational parameters associated with thesubject of measurement include at least one of: speed; dynamic load; andbearing temperature
 7. The method of claim 1, wherein the data sourcesreside in a railroad environment and external factors associated withthe subject of measurement include at least one of: weather; and usagehistory.
 8. The method of claim 1, further comprising integratinganalytics functions including at least one of classification, predictivemodeling, association rule mining, and pattern recognition.
 9. Acomputer program product comprising a storage medium embodied withmachine-readable program instructions, which when executed by acomputer, causes the computer to implement a method, the methodcomprising: collecting data from a plurality of data sources, the datastored in tables each corresponding to a subject of measurement;identifying common fields shared across the tables; merging at least aportion of the data across the tables having the common fields; andcreating an integrated data model based on results of the merging. 10.The computer program product of claim 9, wherein the tables include afirst table and a second table, the first table storing informationabout a first subject of measurement, the information collected over afirst period of time, and the second table storing information about asecond subject of measurement that is different than the first subjectof measurement, the information about the second subject of measurementcollected over a second period of time that partially overlaps with thefirst period of time; wherein the merging includes merging data sharingan overlapping period of time between the first period of time and thesecond period of time.
 11. The computer program product of claim 9,wherein the tables include a first table and a second table, the firsttable storing information about a first subject of measurement, theinformation collected by a first detection device, and the second tablestoring information about a second subject of measurement that isdifferent than the first subject of measurement, the information aboutthe second subject of measurement including a measurement of a physicalparameter that is common to the first subject of measurement and thesecond subject of measurement; wherein the merging includes merging datathat shares the physical parameter that is common to the first subjectof measurement and the second subject of measurement.
 12. The computerprogram product of claim 9, further comprising instructions forimplementing: applying the model to new data received from the datasources and performing failure pattern analysis and failure causalanalysis on the new data.
 13. The computer program product of claim 9,wherein the data sources reside in a railroad environment and physicalparameters associated with train wheels and tracks as the subject ofmeasurement include at least one of: weight; flange thickness; flangeheight; and rim thickness.